The familiar model of known strip-holders consists of a handle, a steel-bows, and a gripping device for the fixing and tensing of a steel-strip covered on one side or both with abrasive material. The steel-strip is inserted over the outer opening of the steel-bow into the grip-openings, i.e., the gripping-clutches cut into the opposite ends of the steel-bow, and then tensed with a six-edge spanner. After fixing the steel-strip in the gripping-clutches, it is tensed with a six-edge spanner engaging the gripping-clutches and by means of a tensing-roller holding the forks of the steel-bow.
Although such an appliance, manufactured by the LM firm in Turku, Finland--by contrast with other such appliances in use with a cutting-disc fitted on to a handgrip, makes possible accurate approximal abrasion, particularly of the bigger teeth with a narrow cervix and a wider incisive tooth-edge whereby the extent of the approximal reduction of the tooth width--through the use of one- or two-sided strips with increasing abrasive granulation, can be controlled, and also the risk of soft tissue injury is substantially reduced, in practice however, this familiar strip-holder has still disadvantages.
Thus the device is containing a lot of moving parts the maintenance of which requires the use of graphite grease or machine oil, so that the sterility of the appliance cannot be absolutely ensured. Further, it is extremely cumbersome to insert the steel-band between the gripping-clutches since it can only be replaced after disengaging the tensing-roller and opening the gripping-clutches with a six-edge spanner while pressing with the finger against the tensed steel-band. The fixing and tensing of a new steel-band consequently requires, in reverse order, its insertion into the gripping-clutches i.e., grip-openings its fixation in the grip-openings of the gripping-clutches and, with the help of a six-edge spanner, in the gripping mechanism. Subsequently, the excess steel-band must be removed with special pliers and the fork of the strip-holder must be properly set, i.e., tensed, by engaging and adjusting the tensing-roller.
Since, for the use of the strip-holder in interproximal space, the steel-band must be moved to and fro, and since its bow consists of two forks running parallel to each other above the gripping-clutches, the fork ends and the gripping-clutches must be introduced deeply into the mouth during therapy.